Dishwasher



I NOV. 4, 1 930. WALKER 1,780,452

DISHWASHER Filed duly 27, 1927 2 Sheets-Sheet 1 .Z'NV NTOR NOV. 4, 1930. R- 1,780,452

DISHWASHER Filed July 27, 1927 2 Sheets-Sheet 2 INVENTOR )h-r/vass W BYWJZYTTO Nays.

Patented Nov. 4, 1930 UNITED] STATES PATENT OFFICE" FORRESTA. WALKER, 0F SYRACUSE, NEW YORK, ASSIGNOR TO WAIiKER DISHWASHER CORPORATION, OF SYRACUSE, NEW YORK, A CORPORATION OF NEW YORK DISHWASHER Application filed July 27,

This invention relates to a mechanical dishwasher in which a rotary impeller involvlng the use of a container for the dishes and washing fluid and suitable means for circulatmg a relatively smallquantity of fluid upwardly and circumferen-tially within the conta ner above the impeller and normal levelof the washing fluid in a manner similar to that set forth in my pending application Serial No. 124,640, filed July 24, 1926, so that the circulating fluid may impinge against the dishes in the trays or baskets and flow back into the bottom of the container for recircu-.

lation.

Theseme'chanical dishwashers are used in private and public kitchens, not only as separate units as shown in my pending application above referred to, but also in combination with sinks to be secured to the underside l of one or the other of the shelves or drainboard similar to that set forth in Patent No. 1,496,946, June 10, 1924, the ob'ect being 'to economize as far as possible in oor space in addtion to the main function of economy of time and labor, and conservation of water and power.

I have found that a relatively small electric motor is particularly well-adapted as the driving means for the rotary water-circua0 lating impeller'and that the cost of manufacture as well as the cost of operation may be kept comparatively low and'thegeneral efliciency of washing the dishes greatly increased if the impeller is constructed and 33 assembled in certain relations to the position and speed of the motor. For example, the batch or batches of dishes operated upon at one time is necessarily limited to the ability and convenience of the op- '4 erator in transferring the batches to and from the washing machne while the vat is constructed and arranged in such manner that a relatively small quantity of water, if properly circulated, will e '45 ing of-the dishes. i

Furthermore, in this type of machine'it is necessary to. maintain a continuous propulsion of the limited quantity of washing fluid upwardly with a more or less concentrated 5 whirling motion and to allowthe return flow if t th h l ec a oroug c Gal-1S the relatlon between the-motor and lmpeller, 95

1927. Serial No. 208,665.

of the water to concentrate in and around the impeller for continuous recirculation and the main object of the' present invention is -to effect this result expeditiously and with a minimum power.

In other words, I have sought to construct the impeller so as to produce a maximum lifting and circulating force upon the liquid with a minimum amount of resistance under a speed of rotation and balance which will prevent excessive wear and strains upon the driving and driven elements. y

Another object is to bring the motor and impeller into closer compact co-axial and direct-drive relation than has heretofore been practised so as to reduce the tortional and vibratory strains upon the driving shaft and impeller and thereby to obtain greater efliciency in the circulation of the washing fluid with a minimum amount of power. .70

A further object is to mount the motor directly upon'a bushing in the bottom of the vat in such manner that the upright motor shaft will be supported entirely by the motor case, irrespective of the bushing.

Another object is to provide the vat with a drainage outlet having a portion clamped between the motor case and bushing and to provide said outlet with a combination water level regulator and valve as a single unit adapted to be operated at will to open and close the valve for discharging thewater I from the vat or maintaining it therein as may the lower portion of the motor and upper portion of the vatbeing broken away.

Figure 2 is a horizontal sectional view taken in the plane of line 2 2, Figure 1.

Figure 3 is an inverted plan of the detion of tached cap for the water level regulator and drainage outlet conduit.

Figure 4 is a vertical sectional View on line 44 of Fig. 6 of the lower portion of a modified form of mechanical dishwasher in which the main body of the motor is shown in elevation while the upper portion of the va-t and. outer portion of the drainage outlet conduit are broken away.

Figure 5 is a side elevation of the detached impeller. k

Figure 6 is a top plan of the impeller and underlying portion of the bottom of the vat.

In order that the invention may be clearly understood I have shown a portion of a conical bottom -1 of a vat adapted to receive the dishes and washing fluid, said conical bottom being provided with separate openings -2 and 3 arranged side by side in more or less close proximity, the opening -2 being formed in the apex of the bottom co-axial with the axis of the vat for re ceiving a bushing 4 while the other opening -'3 is provided with a depressed conical peripheral wall to form a seat for a similar coniform head of a drainage outlet bushing 5. w

The opening -2- and the bushing -4. are circular, the bushing -4 being provided with a more or less conical upper surface and an annular flange 6 resting upon the upper surface of the adjacent porthe bottom -1-, said bushing being also provided with an annular flange 7-- 'fitting snugly within the opening --2. a

The flange 7 is also provided with a plurality of, in this instance three, downwardly extending lugs ,8 v in uniformly spaced relation circumferentially and projecting some distance below the overlying portion of the vat .1- for receiving, and

supporting an electric motor -.9 and a drainage conduit l0.ina manner presently described.

The opening -3 and drainage outlet bushing -5---are-also circular, the bushing -5- being seated at its upper end snugly against the peripheral wall of the opening -3 with its upper face substantially coincident with the inner face of the adjacent portion of the bottom -1- and its lower endextending some distance below the bottom for receiving and partially supporting the drainage conduit -10- in a manner presently described.

The electric motor 9 comprises the main body -11- of the motor case and an upper case section or cap or motor supporting ring 12 having its lower end secured by bolts -13- or equivalent fastening means to the upper end of the case section 11- and its upper end secured to the lugs---8 of the bushing --4 by clamping screws 14- hereinaftermore fully described, the motor sections -11- and -12 being preferably circular and arranged co-axial with the axis of the vat -.1.

The drainage conduit -10 is provided with a horizontal extension 15 having a circular opening -15- 'therethrough coaxial with the axis of the vat -1 and adapted to receive the flange 7 of the bushing 4 andalso the adjacent portion of the lugs -8 which together with the flanges 7 fit snugly against the peripheral wall of the openin -15- to hold the extension 15- and drainage conduit -10 against lateral displacement.

The upper end of the section 12 of the motor case is also provided with a circular opening -16 of substantially the same diameter as the openings 2 and 15 in the bottom of the vat -1- and extension -15 respectively so that the outer faces of the lugs -8 may fit snugly against the in ner peripheral wall of the opening l6 and thereby to hold the motor in coaxial relation to the axis of the vat.

The top face of.the section -12 is engaged with the underside of the extension 15 of the drainage outlet -10 so that the clamping screws -14 serve to hold the bushing 4 and adjacent portion of the bottom of the vat -1 together wlth the extension 15 and motor case section -12- against relative axial movement.

The lugs -8 are provided with inwardly tapered-peripheral sockets -17- while engagement of its flange 6- with the up er' surface of the bottom of the vat 1- an at the same time forcing the motor case section -12 against the bottom of the extension 15- and; simultaneously forcing the extension 15 against the bottom of the vat -1 for firmlyholding those parts against relative axial motion, it being understood that the distance between the axes of the sockets -17 and lower face of the flange -'6is somewhat less than the distance between the upper surface of the bottom of the vat -1- engaged by the flange 6 and axes of the screws --14. to allow a reasonable amount of take-up for-wear of the-walls of the conical sockets 17 and conical inner ends of the clamping screws and thereby to assure a firm clamping of the bushing -4'-, extension and motor ease section 12 to each other and to the bottom of the vat.

The bushing -4 is provided with a tubular post -18, extending upwardly therefrom into the interior of the vat--1 coaxial'therewith and having its lower end am etrically opposite sides thereof and conabove the tubular post -18 in spacedrrelation thereto to avoid frictional engagement 7 therewith or with the bushing .-4 so that the shaft is supported entirely at its lower end by the bearing as -20- in the upperend of the motor case 1, the purpose of which is to enable the motor -9' with the shaft 19 thereon to be placed in operative osition upon the bushing 4 without ma ing any special or laborious effort to maintain exact co-axial alinement of the bushing 4-- and post 18 with the axis of the armature shaft as would be necessary if the shaft 19 had a bearing in the bushing or post.

A rotary impeller '21 is provided with a vertically elongated hollow hub 22 having its upper end closed and provided with an internal nut 23-'- rigid therewith, said nut being screwed upon the reduced upper threaded end 24 of the shaft '-19 to cause the impeller to rotate with the shaft and also to permit the impeller to be removed from the shaft when desired.

The hub 22- of the impeller extends downwardly from the top of the shaft 19 to-a plane close to the upper face of the bushing 4 so as to surround said post but in spaced relation thereto to avoid friction therewith whereby the impeller will be supported entirely from the upper end of the shaft, it being understood that the interior diameter of the hub -22- is. somewhat greater than the external diameter of the post to afford the desired clearance.

The hub 22 is provided with similar blades 25 projecting. laterally from di stru'cted with particular relation to the volume of water operatedupon and also to the the necessary upward lift and circumferential circulation of the water and also with particular relation-to the angle of inclination of the conical bottom. 7

That is, the rotation of the impeller above certain speeds tends to displace 1 the water from the center to the periphery of the,vat and thence upwardly along said periphery with a more or less whirling motion but such a result would not be efiicient inv thoroughly washing the dishes inthe trays or baskets which are usually supported in the vat, in one or more planes above the'impeller and it, therefore, becomtas necessary to construct the blades'so as to enter the mass of water near the center with a' minimumresistance and then to gradually lift the water and retard its centrifugal throw to such an extent as to cause the main body ofthe water tobe deflected upwardly with a more or lessconical circumferential circulation and in order to accomplish this result the blades are elongated vertically and more or-less spirally in reference to the axis of rotation so as to incline from their upper ends downwardly in the irection of rotation, the angle of in-' clination gradually increasing toward thelower ends ofthe blades so as to pick up the body of water near the center with a minimum resistance and then gradually deflect the same upwardly at a steeper angle to emerge from the upper ends in more or less fan-shaped streams which are carried circumferentially around the interior of the vat.

The portions of the lower ends of the blades adjacent the lower 'end of the hub are provided with laterally projecting flanges 26 I inclining laterally and downwardly at a slight angle-to a horizontal plane passing therethrough so as to enter the water with a minimumresistan'ce as the impeller is rotated in the direction indicated by arrow w, Figures 5 and 6. i V

- The diameter of the impeller is less than half the interior diameter of the vat atthe normal level of the water therein as determined by a level regulator hereinafter described while the vertical height of the impeller is greater than the-depth of the norinal quantity of water in the vat so that the. lower ends of the propeller blades of greatest angle of inclination project into the body of water while the upper ends of the blades project above the normal level of said body but when the impeller is rotated the lower 1 ends of the blades pick up the waterwith a minimum resistance and gradually-forces the .same upwardly along the inclined upper surface thereofuntil the water emerges from the entire area of the interior of the vatwithconsiderable force to return by gravityto the bottom of the tub for recirculation. speed .of the motor requisite for producing to bottom thereof for retarding the centri ugal throw of the water as the impeller is rotated, the obtuse angle of the flanges serv- I upper edges of the blades in the form of fan'- I shaped streams which are carried around the ing to assist in producing the fan-shaped streams emerging from the upper ends of the blades while the upward lift of the vwaterproduced by the rotation of the impellers together'with the upward momentum imparted to the water causes such water to pass through the trays vand againstthe dishes with an upward circumferential motion to effect .a thorough cleansing of the dishes by angular I impact of the water therewith.

- If desired, a soft packing ring 27 of rubber, felt or equivalentimaterial may be interposed between the nut -23- and outer the interior of the vatinto the tube 18.

Water level regulator and drainage control The drainage conduit 10- lies beneath one side of the vat 1- and is provided intermediate its ends with anopening 28 in its upper side registering with the opening 3 in the bottom of the vat for receiving the lower end of the bushing 5 to which it is clamped by screws 29- or equivalent fastening means accessible from the interior of the vat, said opening having an annular enlargement in its upper'face provided with a conical peripheral wall 30 adapted to engage the lower conical surface of the peripheral wall of the bottom 1 around the opening -3 through the medium of an interposed packing 30, Figure 1, to form a liquid-tight joint.

The outer end of the drainage conduit 10 is provided with an outlet 31- adapted to 'be connected to any available waste or soil pipe and having its peripheral wall tapered downwardly in the form of a segment of a sphere to form a valve seat for a vertically movable valve and water level regulator 32-.

The valve seat or outlet -3L is disposed in a horizontal plane below the level of the opening 3 in the bottom of the intermediate portion of the conduit which is inclined laterally and outwardly toward the outlet -31- to allow all of the water to be drained from the lowermost level of the interior of the vat.

The combination valve and liquid level controller -32- is tubular and disposed in an upright or vertical plane and has its lower end provided with a tapered peripheral sur face adapted to seat inthe corresponding opening -31- when closed as shown in Figure 1, the upper end of the member 32 being provided with an upwardly flaring opening at a level some distance above the upper surface of the bushing 4l -and in a plane between the lower and upper ends of the impeller '21- or in a plane just above the level of the drainage opening 3 in the bottom of the vat 1 and is provided with a cross bar 33 to which is connected the lowerend of an upright operating rod 34 having its upper end extending to a suitable height for convenience of operation and provided with a handle -'35 for that purpose.

' at their opposite I downwardly projecting lug The portion of the conduit -10 adjacent the outlet --31 extends upwardly above the upper end of. the member -32- when the later is seated in the outlet -31- and is provided at its upper end with a cap section 36-' held in place by screws -37- to form a guide forthe rod -3 l-, said cap section 36- being provided with a central opening -38 through which the rod 4 extends.

The intermediate portion of the rod .--34- adjacent the underside of the cap section 36- is provided with an annular groove 39- adapted to receive a palr of coiled springs -40- which are arranged on opposite sides of the rod and are connected ends to suitable pins -44 on the underside of the cap section 36 for tensioning the coiled springs against the periphery of the grooved portion --39 for frictionally holding the valve -32-- in its extreme open position to permit drainage of the water from the vat erably composed of sections 34 and --34f' arranged end to end and coupled togather by an internally threaded clampin nut -42- engaging the upper threaded en of the section -3 l and an enlarged flange --43 on the lower end of the section 34:II I

In the modified form of my invention shown in Figure 4 the bushing as 4- is threaded externally and tightly screwed into an insulating-sleeve 50- WlllCll is firmly secured in a central opening in the upper case section as -12-, said bushing being additionally clamped in place by a nut --51- engaged with the threaded portion thereof between the upper end of the case section 12'- and extension -15 of the drainage conduit 10'--, 50 being extended between the adjacent faces of the nut 51 and upper motor case section 12- as shown in Figure 4:.

the insulating I The conduit --10 is provided with a -52- adjacent one side of the motor case section -12-, said lug having a threaded opening -53- for receiving a screw 54 which projects into an opening -55- in the adjacent side of the case section -12'-- to hold the motor case and drainage conduit --10"- against,

relatively angular movement.

The nut as -23'- in the upper end of the hub of the impeller 21- is preferably made of insulating material and secured directly to the upper end of the shaft for holding the impeller in operative position on said shaft to rotate therewith.

The insulations -50 and liability of short circuits or leakages of the -23- are placed inthe positions shown to'reduce the pens ed with as shown in Figures 1 to insomewhat smaller than shown 1 and that'a shield 56 is placed around i the shaft -19 just below the top of the case section 12 to deflect any water which may possibly, but improbably, pass into the interior of the tubular post --18 away from the armature of the motor, while the bushing -5 is screwed in place.

Operation When placing the motor 9-in operative position the bushing 4- will first be inserted in the opening in the apex of the bottom of the vat 1 after which the extension 15- of the drainage conduit -l0 is placed inoperative position upon the bushing following which the motor -9 with the shaft l9 thereon will be placed from the bottom upwardly against the underside of the extension l5- and secured in place by the tightening of the screws --l4 which, it will be noted, are accessible from the outside or periphery of the motor, it being understood that during this installation. of the motor the shaft will be projected upwardly throughthe tubular post --18.

When the drainage conduit -10-- is placed in operative position in the manner just described, the peripheral walls of the annular enlargement in the upper face thereof will be brought into engagement with the peripheral wall of the opening -3 after which the bushing 5 may be inserted in the registering openings in the bottom of the vat -1- and top of the conduit 10 and secured in place by screws -29- 'which are readily accessible from the interior of the vat. Y

The propeller -21- may then be screwed c upon the upper end of the shaft 19- and rotated with said shaft in the direction indicated by the arrows, Figure 6, by the operation of the motor'9 which may be controlled bytany suitable switch in the motorcircuit, not shown.

, When the conduit --10 with the water level regulator and valve -3 2 therein is installed in the manner described and remains in its closedposition, water may be introduced from any available source and in any desirable manner into the interior of the vat l and allowed to flow into the conduit 10- until itreaches the level of the top of the member 32-- whereb the water will overflow through the mem er -32 and outlet as 31 to the Waste pipe not shown, .thereby establishing a pre-deten,

\ ,minedlevel of the water' in the vat which cannot be exceeded beyond the level of the outwardly through the openings -31-- and 31- to the waste'pipe.

During the rotation of the impelleir2l the'water is first picked up by the lower ends form of fan-shaped streams which are given a whirling or circular motion by the force of upward propulsion and centrifugal force.

of the blades 25 and thereby deflected upwardly at the top of the blades in the- The centrifugal displacement of the water,

by the rotation of the impeller blades is retarded to a considerable degree bythe flanges along the outer edges of the blades and by reason of their angular relation to the main bodies of the blades assist in forming the'desired fan-shaped streams of water emerging from the upper ends of the blades when the impeller is rotated at the desired speed according to the vertical distance through which the water is obliged to travel and also the circumferential sweep of the streams of water depending, it being understood that the diameter of the propeller and form of the blades have a definite relation {0 tlie ,diameter of the vat at the normal water eve It will also be noted that the motor shaft Another and most important advantage of this construction is that the motor arma-' ture shaft is brought close to the'load or to the impeller --21 thereby reducing to a minimum the liability of tortional strains and vibrations of the impeller when rotated at suflicient speed to accomplishthe desired,

lifting and circular motion of the water, all of which conserves the power required for operating the motor and alsoecon'omizes in the use of water necessary for' thoroughly washing or.rinsing the dishes.

It is to be understood, of course, that after the-dishes have been thoroughly washed and it is desired to rinse the same the fresh rinsing water may be introduced into the vat in which case'the valve member 32- could be left open to allow the water to drain off as fast as it was introduced.

" WhatfI claim is 1. In a mechanical dishwasher, a vat, an apertured bushing'l extending through an opening in the bottom'of the vat and provided with a flanged head engaging the inner face of said bottom, a municating of the vat and provided with an extension loosely surrounding the portion of the bushing adjacent the bottom of the vat, and a motor-supporting ring movably secured to the lower end of the bushing and clamping the drainage conduit comconduit extension and bushing to the bottom.

of the vat.

2. In a mechanical dishwasher, a vat having a drainage outlet in its bottom, a bushing secured in an opening in the bottom of the vat at one side of the drainage outlet, a drainage conduit communicating with said outlet and provided with an extension surrounding the bushing, a motor supporting-ring operatively mounted on the lower end of the bushing for clamping the bushing and extension to the bottom of the Vat and movable means for holding said ring in operative position.

3. In a mechanical dishwasher, a vat having a conical bottom providedwith an opening in its apex, a bushing extending through said opening and having its upper end resting upon the upper surface of the bottom around said opening, a drainage conduit communicating with the interior of the Vat and provided with an extensionsurrounding the bushing adjacent the underside of the bottom ofthe vat, a motor-supporting ring having its upper end surrounding the lower end of the bushing and abutting against the underside of the extension of the drainage conduit, and means for securing said ring to said bushing.

4. In a mechanical dishwasher, a vat having separate openings in the bottom thereof,

one of said openings being for drainage purposes, a 'dralnage conduit and a drainage bushing engaging respectively the outer and inner faces of the marginal walls of the drainage opening, adjustable means connecting said conduit and bushing for tightening and releasing the same,.said conduit having an integral apertured extension other opening and engaging the underside of the walls' thereof, a bushing engaging the upper face of the marginal wall of the second-named opening, a motor-supporting ring adjacent the underside of the conduit extension around the aperture therein, and adjustable means connecting the bushing and motor-supporting ring for holding the conduit extension and bushing in engagement with the lower and upper faces ofthe marginal wall of the second-named opening.

In witness whereof I have hereunto set my hand this 7th dag; of July, 1927.

F RREST A. WALKER.

with an opening in the bottom surrounding the? 

